How to Make It
In a small saucepan, heat the milk until bubbles appear around the edge. In a heavy medium saucepan, melt the butter. Add 1/2 cup of the flour and cook over moderate heat, whisking constantly, until golden, about 2 minutes. Add the hot milk, 1/3 cup at a time, whisking vigorously, until smooth. Cook over low heat for 5 minutes, stirring often. Stir in the turkey and ham and remove from the heat. Season the mixture with white pepper; the ham will provide enough saltiness.
Spread the mixture in an 8-inch-square baking dish, and press a piece of plastic wrap directly on the surface. Refrigerate until chilled and semifirm, at least 6 hours or overnight.
Pour the remaining 1/2 cup of flour into a bowl. In another bowl, lightly beat the eggs. Pour the bread crumbs into a third bowl. Remove the plastic wrap from the mixture and cut into 36 squares. Using floured hands, dip 1 square into the flour and roll into a soft ball. Coat the ball with beaten egg and then bread crumbs. Set the croquette on a tray lined with wax paper. Repeat with the remaining squares. Refrigerate the croquettes for at least 1 hour to firm them up.
In a medium saucepan, heat 1 1/2 inches of olive oil to 350°. Fry the croquettes in batches without crowding until golden brown, about 3 minutes. Drain on paper towels. Reheat the oil between batches and remove any stray crumbs. Serve the croquettes warm.